no spark 1970 T350

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dollydog
Yeah Man, the Interstate
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Country: england
Suzuki 2-Strokes: several gt250 ramairs

Re: no spark 1970 T350

Post by dollydog »

russ: you've got [1] an air leak. or [2] lack of oil in the mixture - when it's about to be fired.
if you'd taken every bit of good advice in this thread and done it properly, the bike would be running properly by now. there's something you've either missed or skimped on. when you take the carbs off, are the flanges wet? are the 'o' rings sealing? are the black insulators cracked? you need a magnifying glass on these, as honestly, the cracks are very difficult to see.
are both slides going up at exactly the same time when you open the throttle? go through all the good advice in this thread and do it thoroughly. you'll sort it. my money is still on an air leak :D
you mentioned earlier that one side was getting hot and not the other, is it still doing it? if it is, concentrate on the side that isn't running. why isn't it? what's causing it? sort that first, then sort your air leak :D :D :D
cheers, dd.
GTS250 road registered. TS250 engine, Ramair frame.
GT250 big bang road registered. Both pistons fire the same time. USD forks.
GT285 road registered. Overbored - 58mm and TS125 +2 pistons fitted.
GT10 road registered. '65 T10 engine, GT250 frame.
sportston
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Suzuki 2-Strokes: FZ50, GP100, RG125 Gamma, GT380, Bandit 1200S

Re: no spark 1970 T350

Post by sportston »

Yes an air filter does matter to the amount of air you suck in. Ditch the rotting one and fit a new one (Make sure it has been oiled correctly if it is a foam element. Don't oil if it is the paper type).
+1 on what DD said. You must have missed something.
What results did you have when you tried spraying Easy Start?

By the way...ignore air leaks at your peril! It will give you a lean mixture and can cause seizure and/or a hole in your piston. The last thing you need on an air-cooled engine is a lean mixture.
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russt
On the street
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Suzuki 2-Strokes: 1970 Suzuki T350

Re: no spark 1970 T350

Post by russt »

Thanks for the replies... I seem to get a lower RPM range when I spray easy start around the top of the carbs where the throttle cable goes in. Is their supposed to be some kind of o-ring around it? The rubber boots that go on top of the carbs are little warn. I do not seem to get any other RPM change anywhere else. Also seems to be a little rich on the left spark plug. I have sprayed easy start around the whole engine :D
sportston
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Joined: Wed Jul 10, 2013 12:04 pm
Country: England, UK
Suzuki 2-Strokes: FZ50, GP100, RG125 Gamma, GT380, Bandit 1200S

Re: no spark 1970 T350

Post by sportston »

Hmm. That shouldn't make any significant difference.
Here are a few things to consider;
Have the top of the carb lids still got their rubber rings intact? (On many carbs they have an o-ring inside the screw on lid. Though I doubt that is the cause of your main problem)
Are the carb slides worn? Unless the revs dip by quite noticeably I doubt that it would be sucked through around the cable guides unless the air filter is severely clogged, intake blocked and/or carb slides very worn.
However...are you sure it wasn't being sucked in somewhere else that is close to the cable guides? e.g. porous or cracked vacuum pipe running close by or poorly sealed intake pipes or leaky choke valves.
By how much did the revs dip?
If it dips only very slightly and equally by spraying on both sides in turn, then I would consider ignoring this symptom and instead concentrate on what is different between left and right. You mentioned one side appears to be running richer than the other... You must find out why.
For some reason one side is different. Examine the small things carefully.
Is your choke valve seating correctly? (is the rubber hard and cracked with age? Or is the seat beneath it corroded or damaged?)
Is the left exhaust clogged more than the right?
Keep at it and eventually you will find the culprit, though it may take a lot of theorising and hair-pulling.
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